Do you have a problem with the backlight on your laptop? If yes, you are not alone, that’s one of the most common laptop problems. In most cases the screen inverter is the culprit. Here are some LCD screen backlight failure symptoms that could be related to a bad inverter board:
- Laptop boots as usual but after some time the screen blacks out. You still can see an image on the screen but it’s very dim. You might even use a flashlight to see it better. Sometimes the backlight comes back for a while but then goes off again. In some cases you can turn the backlight on if you tap rapidly on the lid close switch.
- The screen always stay black and the backlight never comes on but you still can make out an image on the LCD. It’s dark, but the image is still there.
-In some cases you might hear a buzzing noise coming from the area where the inverter board is located, it’s on the bottom part of the display assembly.
NOTE: if you cannot see an image on the screen, most likely you have a different problem and there is nothing wrong with the screen inverter.
Other related articles:
Laptop has bad video on the LCD screen. What is wrong?
Notebook display assembly diagram. How image appears on the screen.
How to troubleshoot and fix laptop video problems
How to replace laptop backlight lamp (CCFL)
Here’s an example of replacing the FL inverter board on an IBM ThinkPad T41 notebook. This guide will work fine for any other IBM notebook. Replacing screen inverter on other notebooks like Dell, HP, Toshiba, etc… will not be much different.
First of all, unplug the AC adapter and remove the battery.
In order to access the inverter board you’ll have to remove the LCD screen bezel. On most laptops screws are hidden behind screw seals. In this case we have 5 screw seals on the front. Carefully remove the seals with a sharp object and glue them on the LCD bezel, in this case you will not lose them. Remove all screws and mark them somehow so you are not confused when you assemble the notebook back.
Some laptops also have screws on the side of the display. This notebook has 3 screws on each side. Remove screws seals and then remove screws.
Start removing the LCD bezel with all fingers. Carefully wiggle the bezel to release plastic latches. Never use any sharp object during disassemble because you can accidentally damage the screen.
If latches are very tight you can use a guitar pick to unlock them. Insert the guitar pick between the LCD bezel and cover and carefully move it alone the side.
This notebook allows you to replace the inverter board without removing the LCD bezel completely. Lift up the bottom part of the bezel and remove one screw securing the inverter board to the LCD cover. This location is very common for the screen inverter. On most laptops you’ll find it under the display bezel below the screen.
Carefully lift up the FL inverter and rotate it a little bit. Unplug cables on both sides. The left side of the inverter board connects to the video cable, the right side to the backlight bulb (CCFL tube) inside the LCD screen. Remove the inverter and replace it with a new one.
To find a new inverter board (and any other spare part too) for any IBM notebook you should use the FRU number from the part.
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April 22nd, 2007 at 2:15 pm
Chaz,
Your laptop worked fine for 3 hours, right? I don’t think it would work for 3 hours with a bad cable. Maybe you got a bad inverter? Did you buy a used inverter? Can you ask the seller for a replacement and try it again?
April 21st, 2007 at 6:58 am
84 those guys who sell at eb…y they dont care if you fix your laptop or not, if you want have good service go http://www.impactcomputers.com they are going o tell u the inverter you need and they can help u with the problem too, becareful the cheap no all the time is better, I can fix your laptop if u are close to kansas city MO my email is castgeor@msn.com
April 21st, 2007 at 6:52 am
85 sell you laptop for parts replae the video card is a major fix becasue u must disamblie the lcd and the laptop too everything is the left top corner conect a couple wires to the but u need dissambly the lcd god luck if u want sell it mail me castgeor@msn.com
April 21st, 2007 at 6:49 am
Answer to 86 are u sure is the right inverter? try to gt the phone number from impact computers and select the option 2 the guy in that extension is excelent and he is going to tell you if u have the right inverter, make sure you have the lcd part # more if your laptop is dell is http://www.impactcomputers.com the price is alittle high but you receive the corect part if u can have the lcd disambly better.
April 20th, 2007 at 8:31 am
Hi,
I replaced the inverter, but it didn’t resolve. Any other ideas?
Thanks,
Mitch
April 19th, 2007 at 8:11 pm
Hi I have a T20 with no video at all..what can I do ..pls help me?
April 17th, 2007 at 6:28 am
First of all, thanks for the previous help.
I got the inverter that I’d ordered, but despite assurances from the seller that it works on all HP and Compaq laptops with a 15 inch screen, it didn’t do anything to solve my problem. It also wasn’t the same model / part that I’d taken out, so I’m hoping THAT is what the issue was and ordered one that I’m absolutely certain is the same part number and everything.
I’ve powered up the screen with the old inverter, with the different inverter that was the wrong part number, and without any inverter at all and it’s all the same level of ‘dim’ … so, in that regard, I’m still hoping that’s the issue.
My question now is, if I get that new, correct inverter in there and that doesn’t solve the issue, what’s my next course of action … ?
April 16th, 2007 at 11:24 pm
CJ,
Look what I found for you. Here’s a guide for upgrading the video card on an Dell Inspiron 8500/8600 laptops. Looks like the video card is a discrete module in this laptop. You can follow the guide and try reseating the video card. It’s possible the video card was dislocated when you dropped the laptop and doesn’t make a good connection with the motherboard. Try reseating it and see if it helps.
April 14th, 2007 at 7:36 am
Hey there. Thanks for enlightening us technically challenged folk.
I tried changing my inverter and it worked fine for 3 hours or so, then it just wnet black again. I can get it to work again briefly by pressing the screen cable down next to where the inverter is and opening and closing the screen. There’s a knack to it. But even that’s stopped working. What is wrong with the thing? I only need it to last me a few more months.
Is it the screen cable? Do I go find out how to change that now?
Thanks, Chaz.
April 13th, 2007 at 3:44 pm
I have a Dell Inspiron 8500 that I dropped
The upper half of the screen is fine! the lower half is lit, but is actually displaying the last line of the top half of the screen all the way to the bottom.
At first, I hooked up an external monitor and it was working full screen there, but eventually it turned blue, then green now won’t work at all.
Suggestions? Think it is the video card which i understand is part of the mother board, or think it is the screen and the video card?
I’ve been laid off work and need to find a solution fast and inexpensively of course!
thanks for any help you can be.
cjloveslife1960@yahoo.com